The 1905 Revolution in Russia occurred in the midst of a major international war waged between Japan and Russia from February 1904 to September 1905. We know very little about the impact of the revolution on the Japanese soldiers fighting at the front. Through an exhaustive study of personal materials of soldiers—namely, personal diaries, particularly those of the lower ranks—this essays offers a glimpse into the mentality of Japanese soldiers on the battlefield as they faced enemy soldiers. How did they describe their feelings toward the Russians? Did they learn about the 1905 Revolution while in the trenches? If so, what were their reactions? Did the revolutionary turmoil in Russia affect the fighting spirit of the Russian and Japanese soldiers? This was a pivotal moment in the history of both Russia and Japan. A methodological approach that takes into account the history from below can shed new light on popular Japanese attitudes toward the revolution.